Blue shark near the Azores in the North Atlantic Ocean

© Nuno Sa/Minden Picture

Chasing currents. Explorer of the sea

This blue shark is swimming near the Azores, a chain of islands about 850 miles west of mainland Portugal. The inspiration for its name comes from the colour of its back, which can vary from a light blue to a darker shade. Its slender, tapered body is propelled through the water with agility and grace by a long tail fin that sweeps from side to side.

Listed as 'near threatened', blue sharks are found off the coast of every continent except for Antarctica, making them the most widely distributed of all sharks. Swift and powerful swimmers, blue sharks migrate long distances - 1,200 to 1,700 miles - in a clockwise pattern, following ocean currents in search of food, a mate and the perfect water temperatures. They prefer water on the cooler side, between 10 and 20 degrees Celsius, and will swim down 1,000ft to find it.